constant for Event AMT bitwidth.

chain/events/filter/event.go

@@ -444,7 +444,7 @@ func (m *EventFilterManager) loadExecutedMessages(ctx context.Context, msgTs, rc
 			continue
 		}
 
-		evtArr, err := amt4.LoadAMT(ctx, st, *rct.EventsRoot, amt4.UseTreeBitWidth(5))
+		evtArr, err := amt4.LoadAMT(ctx, st, *rct.EventsRoot, amt4.UseTreeBitWidth(types.EventAMTBitwidth))
 		if err != nil {
 			return nil, xerrors.Errorf("load events amt: %w", err)
 		}

chain/types/message_receipt.go

@@ -17,13 +17,15 @@ const (
 	MessageReceiptV1 MessageReceiptVersion = 1
 )
 
+const EventAMTBitwidth = 5
+
 type MessageReceipt struct {
 	version MessageReceiptVersion
 
 	ExitCode   exitcode.ExitCode
 	Return     []byte
 	GasUsed    int64
-	EventsRoot *cid.Cid // Root of Event AMT
+	EventsRoot *cid.Cid // Root of Event AMT with bitwidth = EventAMTBitwidth
 }
 
 // NewMessageReceiptV0 creates a new pre FIP-0049 receipt with no capability to

cli/chain.go

@@ -1773,7 +1773,7 @@ var ChainInvokeEVMCmd = &cli.Command{
 			afmt.Println("Events emitted:")
 
 			s := &apiIpldStore{ctx, api}
-			amt, err := amt4.LoadAMT(ctx, s, *eventsRoot, amt4.UseTreeBitWidth(5))
+			amt, err := amt4.LoadAMT(ctx, s, *eventsRoot, amt4.UseTreeBitWidth(types.EventAMTBitwidth))
 			if err != nil {
 				return err
 			}

itests/kit/evm.go

@@ -112,7 +112,7 @@ func (e *EVM) LoadEvents(ctx context.Context, eventsRoot cid.Cid) []types.Event
 	require := require.New(e.t)
 
 	s := &apiIpldStore{ctx, e}
-	amt, err := amt4.LoadAMT(ctx, s, eventsRoot, amt4.UseTreeBitWidth(5))
+	amt, err := amt4.LoadAMT(ctx, s, eventsRoot, amt4.UseTreeBitWidth(types.EventAMTBitwidth))
 	require.NoError(err)
 
 	ret := make([]types.Event, 0, amt.Len())

node/impl/full/chain.go

@@ -661,7 +661,7 @@ func (a *ChainAPI) ChainBlockstoreInfo(ctx context.Context) (map[string]interfac
 // TODO (raulk) make copies of this logic elsewhere use this (e.g. itests, CLI, events filter).
 func (a *ChainAPI) ChainGetEvents(ctx context.Context, root cid.Cid) ([]types.Event, error) {
 	store := cbor.NewCborStore(a.ExposedBlockstore)
-	evtArr, err := amt4.LoadAMT(ctx, store, root, amt4.UseTreeBitWidth(5))
+	evtArr, err := amt4.LoadAMT(ctx, store, root, amt4.UseTreeBitWidth(types.EventAMTBitwidth))
 	if err != nil {
 		return nil, xerrors.Errorf("load events amt: %w", err)
 	}